Aspirin sensitive patients with asthma often experience continuous inflammation of their nasal and sinus tissues, which is complicated by repeated sinus infections (chronic sinusitis). This sinus disease often contributes to asthma attacks. Aspirin-sensitive patients may also have immediate reactions after ingestion of aspirin or nonsteriodal anti-inflammatory medications (i.e. Motrin, Advil, Aleve, etc). Typically, these reactions involve naso-occular symptoms (nasal congestion, runny nose, red/itchy eyes) followed by an asthma attack 30-60 minutes after ingestion of aspirin. Other less common reactions include hives, generalized swelling of the skin, abdominal pain and anaphylaxis (drop in blood pressure). The cause of aspirin sensitive asthma has been linked to inflammatory cells which release certain chemicals called leukotrienes after exposure to aspirin. These leukotrienes are believed to be responsible for not only the immediate reactions seen in aspirin-sensitivity, but also in the chronic inflammation (swelling) of asthma and sinusitis seen in this disease. Leukotriene receptor antagonists are drugs that help block part of the swelling process in the lungs and sinuses. Montelukast is one of these drugs, and has been approved by the US Food and Drug Administration (FDA) for the treatment of asthma. Research has shown that almost all aspirin-sensitive individuals can be made tolerant of aspirin following aspirin densitization. Not only has aspirin desensitization been shown to be effective in stopping the immediate responses after aspirin ingestion, it appears to improve both the asthma and chronic sinusitis in a majority of aspirin-sensitive asthmatics. Aspirin desensitization typically involves slowly increasing aspirin doses over 2-3 days under direct supervision. Once the target dose of aspirin is reached, the patient is continued on a small dose of aspirin indefinitely. Inflammation in the nose and upper airways can be measured by testing different marker of inflammation. One of these markers is nitric oxide, a gas that is produced when airway tissues are inflamed. Other markers are eosinophil cationic protein (ECP), a protein found in blood, and urinary LTE4, which is a compound measured in urine samples. Finally, a direct observation of the sinuses will be done with a CT scan of the sinuses. The purpose of this study is to look at the effect of aspirin desensitization on these inflammation markers, sinus disease, and asthma in patients who are given motelukast before the densitization, compared to patients not given the drug.